21496745 has 8 divisors (see below), whose sum is σ = 25827720. Its totient is φ = 17176320.

The previous prime is 21496723. The next prime is 21496753. The reversal of 21496745 is 54769412.

It can be written as a sum of positive squares in 4 ways, for example, as 5368489 + 16128256 = 2317^2 + 4016^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21496745 - 2¹⁶ = 21431209 is a prime.

It is a super-2 number, since 2×21496745² = 924220091190050, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21496699 and 21496708.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2915 + ... + 7175.

It is an arithmetic number, because the mean of its divisors is an integer number (3228465).

Almost surely, 2^21496745 is an apocalyptic number.

It is an amenable number.

21496745 is a deficient number, since it is larger than the sum of its proper divisors (4330975).

21496745 is a wasteful number, since it uses less digits than its factorization.

21496745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5275.

The product of its digits is 60480, while the sum is 38.

The square root of 21496745 is about 4636.4582387853. The cubic root of 21496745 is about 278.0508550409.

The spelling of 21496745 in words is "twenty-one million, four hundred ninety-six thousand, seven hundred forty-five".